Grease 6 Custard Cups. Cream 1/4 Cup butter, sugar, And Brown SugarTogether in Mixing Bowl With an Electric Mixer For 2 Minutes. AddEggs, And egg Yolk, One at a Time, Beating After Each Until WellBlended. Mix cornstarch And cocoa Together. Slowly Add to CreamedMixture, Beating Thoroughly. Blend in vanilla And Half-And-Half.

Pour a Scant 1/2-Cup Mixture Into Each Prepared Cup. Top Each With aHeaping Tablespoon of chocolate chips. Cover Each Cup With FoilTightly. Pour water Into Pressure Cooker And Set Trivet or SteamBasket on Bottom. Arrange Cups, Pyramid Style in Cooker (3 Cups OnBottom). Lock Lid And Bring to Full Pressure. Reduce Heat ToMaintain Pressure And Cook For 9 Minutes. Release Pressure. RemoveCovered Custard Cups And Place on Cooling Rack to Cool. Remove Foil.Chill For 4-6 Hours. Before Serving, Garnish Each With WhippingCream And shaved chocolate.